I love the box game!!!! I think you might be asking for too much though. Just click anything at all, maybe even looking at the box, moving towards it, moving behind it, anything. Part of the problem is probably clicking too much at one stage. If she nose touches, you click, nose touch, click, you will get stuck in that same pattern. It's hard to avoid, but to get out of it you need to stop clicking what you just did. IF the dog is in the game and they don't get clicked, they get frustrated and should try harder the next time. They may still do a nose touch, but it will be a harder nose touch, or 2 noses touches, or... A harder nose touch is still something different, so i would click it. You need to have a high rate of reinforcement going on so your dog doesn't give up as easily.
I would focus on teaching her to keep trying rather then the specific goal of paw in the box right now. It may help to bring out a new object where she isn't so set on just a nose touch, or to turn the box upside down, or on its side, etc. If you really want a paw right now, then maybe try throwing the treat inside the box so she has to step inside. Even if she doesn't step inside of it, you could click her head going down inside the box, throw another treat, click head going inside, throw treat, click, and then start having her come back to you to get the treat to set her up to do it again.
Just be patient. When you're first trying shaping it's easy to get frustrated and trapped into clicking the same thing over and over and having your dog give up and stare at you. AT least she understands she has to move away from you though! It is also helpful to try and click DURING the behavior and not after. So click while she is nosing, and not she noses, you wait to see if she'll do something else, and then click 1/2 sec late. The later you click the more you're clicking her doing nothing, or actively avoiding the box!